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SharksWithFreakingLaserBeams > Module1-Intro to Lasers > Flashcards

Module1-Intro to Lasers Flashcards

1
Q
  1. When was the first working laser devise used? 2. what type of crystal was used? 3. What color was it?
A
  1. 1960 2.Ruby Crystal 3. Red beam
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2
Q

What is LASER an acronym for?

A

Light Amplification by Stimulated Emission of Radiation

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3
Q

What are the three terms used when comparing normal light with laser light?

A

1.wavelength/color (multi/monochrome) 2.collimation 3.coherent

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4
Q

Units of Measurement: wavelength

A

NM

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5
Q

Units of Measurement: pulse duration (3)

A

US, PICO, NANO

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6
Q

Units of Measurement: pulse repetition

A

Hz

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7
Q

Units of Measurement: ENERGY (2)

A

J or MJ

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8
Q

Units of Measurement: POWER (2)

A

Average (W), Peak (W)

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9
Q

Units of Measurement: Irradiated Area (2)

A

cm^2 or mm^2

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10
Q

Units of Measurement: Energy density

A

J/cm^2

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11
Q

Units of Measurement: Fluence

A

J/cm^2

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12
Q

Units of Measurement: POWER density

A

W/cm^2

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13
Q

Which type of emission is being described?: ENERGY ABSORPTION OF ELECTIONS (VIA ABSORBING A PHOTON), RESULTS IN AN ELECTRON REACHING AN EXCITED LEVEL, THEN THE ELECTRON FALLS BACK TO ORIGINAL STATE WITH THE EMISSION OF A PHOTON

A

Spontaneous Emission

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14
Q

Which type of Emission is being described?: SECOND PHOTON INTRODUCED BEFORE SPONTANEOUS FALL BACK OCCURS, RESULTS IN STIMULATED FALLBACK TO ORIGINAL LEVEL WITH THE STIMULATED RELEASE OF 2 PHOTONS

A

Stimulated Emission

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15
Q

What are the two properties of a photon in stimulated emission that make it the definition of a laser?

A

the photons are IDENTICAL and COHERENT

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16
Q

What principle is this describing? A THEORY THAT BUILDS OFF OF A SINGLE EPISODE OF STIMULATED
EMISSION, IF EACH OF THE TWO IDENTICAL PHOTONS LEAVING THE ATOM STIMULATE OTHER ATOMS TO EMIT AND SO ON….

A

Avalanche Principle

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17
Q

What is the term for this?: MORE ATOMS IN THEIR EXCITED STATE THAN IN THEIR GROUND STATE, THUS CREATED MORE OPPORTUNITIES FOR STIMULATED EMISSION TO OCCUR

A

Population Inversion

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18
Q

Whats the difference between ionizing radiation and non-ionizing radiation?

A

Ionizing-electron breaks away from the atom. Non-ionizing-electron is just excited and stays with electron

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19
Q

What parts of the ElectroMagnetic Spectrum do lasers operate?

A

Visible and InfraRed

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20
Q

What two parts of the ElectroMagnetic Spectrum do lasers use to work on Soft Tissue?

A

Nd:YAG and Diodes = NEAR InfraRed….CO2 = Far InfraRed

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21
Q

What part of the ElectroMagnetic Spectrum does a laser use to work on Hard Tissue?

A

MID InfraRed

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22
Q

What are the 3 main components to a Laser?

A

1.Active Medium 2. Pumping Mechanism 3.Optical Resonator

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23
Q

Which component of a laser gives the laser its generic name? What are some examples?

A

The Active Medium…Erbium:YAG, Diode-semiconductor, CO2

24
Q

What are the two types of pumping mechanisms?

A
  1. rapidly flashing lamp (free running lasers) 2.electrical current field (continuous wave lasers)
25
Q

What are the two Modes of Operation for a laser?

A

1.Continuous Wave 2.Pulsed

26
Q

Which Mode of Operation am I describing? The laser is activated and emission is constant.

A

Continuous Wave

27
Q

Which Mode of Operation am I describing? The laser energy is produced in very short pulses by a flash-lamp.

A

Free-Running Pulsed

28
Q

What are the 4 ways a laser can interact with tissue? Which is the ONLY interaction that is useful in dentistry?

A

RATS! 1.Reflection 2.Absorption 3.Transmission 4.Scatter…..ABSORPTION is the only interaction that can do work

29
Q

What are the three types of absorption that a laser has on tissue?

A

1.Thermal 2. Chemical 3.Acoustic

30
Q

What are the 4 CHROMOPHORES in the tissue that absorb laser light?

A

1.water 2.hemoglobin 3.melanin 4.carbonated hydroxyapatite

31
Q

What are the 2 main chromophores at work in HARD tissue?

A

Water and Carbonated Hydroxyapatite

32
Q

What are the 2 main chromophores at work in the soft tissue EPITHELIUM?

A

Water and Melanin

33
Q

What are the 3 chromophores at work in the soft tissue SUB-Epithelium?

A

1.Water 2.hemoglobin 3.OXY-hemoglobin

34
Q

Temperature effects on tissue- what happens at >37 deg C?

A

Hyperthermia

35
Q

Temperature effects on tissue- What happens at >50 deg C?

A

BACTERIA Inactivated

36
Q

Temperature effects on tissue- What happens at >60-90 deg C?

A

Coagulation and Irreversible PROTEIN DENATURATION

37
Q

Temperature effects on tissue- What happens at >100-150 deg C?

A

Vaporization

38
Q

Temperature effects on tissue- What happens at >200 deg C?

A

Carbonization

39
Q

Temperature effects on tissue- At 50 􏰃C, non-________ bacteria, including ________, are readily deactivated

A

non-SPORULATING…ANAEROBES

40
Q

To achieve hemostasis, a tissue temperature of ____ 􏰃C must be obtained.

A

60 degrees C

41
Q

For removal (excision) of healthy tissue, a temperature of at least ____ 􏰃C must be reached

A

100 C

42
Q

Did you know…soft tissue COAGULATIOn by ____ lasers is 10x more efficient than Erbium lasers

A

CO2

43
Q

Did you know….soft tissue ABLATION by CO2 lasers is 1,000x more efficient than _____ lasers

A

diode

44
Q

Did you know…InfraRed CO2 lasers at 10% absorption has 4x less _____ than Near InfraRed and 3x less ______ than Erbium

A

HEATING…HEATING

45
Q

Did you know..coagulation depth is PROPORTIONAL to ________ depth

A

absorption

46
Q

What is the RANGE for possible diameters of blood vessels in the SUB-Epithelium? What is the AVG?

A

21-40 micrometers…31 micrometers

47
Q

Which laser is most likely to cause wide spread tissue damage during coagulation?

A

Near-IR DIODE

48
Q

Which laser is highly accurate and efficient, but has poor coagulation efficiency?

A

Mid-IR Erbium lasers

49
Q

Which laser is highly efficient and accurate and has excellent coagulation?

A

CO2 laser

50
Q

A PROPERTY OF EM WAVES IN WHICH EACH WAVE IS OF THE SAME WAVELENGTH AND PRECISELY IN PHASE WITH EACH OTHER

A

Coherent

51
Q

A PROPERTY OF EM WAVES WHERE ALL THE WAVES ARE PARALLEL

A

Collimated

52
Q

Peak Power = what / what?

A

peak power = pulse energy (J) / pulse duration (s)

53
Q

Average Power = what / what?

A

avg power = pulse energy (J) / Pulse rate (Hz)

54
Q

Decreasing the diameter of a tip by 2x decreases the area working on by a factor of __x, therefore its a __x increase in the ______

A

4x…4x increase in the FLUENCE

55
Q

Safety-what is the definition of MPE?

A

Maximum Permissible Exposure-level of exposure without injury

56
Q

Safety-does focal magnification have an effect on eye injury from a laser?

A

YES…a 10^5 GAIN on the retina (1mW/cm^2 into eye = 100 W/cm^2 on the Retina!!!!!)

57
Q

What thickness of mask should be used for the plumes made?

A

0.1 micron thick

SharksWithFreakingLaserBeams (3 decks)

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